Demography ofRumex acetosellain lowbush blueberry (Vaccinium angustifolium)

Summary The demography of Rumex acetosella ramets and seedlings was monitored within and between blueberry clones over the two-year lowbush blueberry production cycle in Nova Scotia, Canada. Overwintering ramets constituted the majority (>70%) of the flowering ramet population. A small proportion of ramets emerging in May and June flowered, but no ramets emerging between July and November flowered in the year of emergence. Emergence of new ramets was season-long and ramet populations were regulated by a cycle of birth and death in each production year. Ramet populations in blueberry patches had higher growth rates and lower mortality than ramet populations in bare soil patches in the non-bearing year, resulting in large net gains to ramet populations in blueberry patches during this production year. Ramet population growth rates and mortality were similar in blueberry and bare soil patches in the bearing year and net ramet populations declined during this production year. Survival rates of overwintering and new ramets varied, but ramets from both the overwintering and monthly cohorts contributed to a distinct ramet age structure at the end of each season. Seedling survival ranged from 6 ± 6 to 51 ± 12% across sites, and no seedlings flowered in the year of emergence. Transition probabilities of ramets and seedlings were used to develop a life-cycle model of R. acetosella for the 2-year lowbush blueberry production cycle. This model has utility in developing new management strategies for R. acetosella in lowbush blueberry.